(1) Field of the Invention
This invention relates to a tape recorder, especially to a tape recorder the magnetic head of which is turned over 180.degree. upon each change-over of the running direction of a magnetic tape.
(2) Description of the Prior Art
In some of conventional tape recorders equipped with an auto-reverse function, the magnetic head is turned over 180.degree. upon each change-over of the running direction of a magnetic tape. Turning-over mechanisms of this sort are constructed generally as shown in FIG. 6. Namely, a turning shaft 64 is fixed on a head mount 62, which carries a magnetic head 61 thereon, with the central axis of turning of the turning shaft 64 being coincided with the central axis of turn-over of the head 61. The turning shaft 64 is also supported turnably on a bearing 65. By turning a disk-shaped flange 66 secured fixedly on the lower extremity of the turning shaft 64, the head 61 is caused to turn about the central axis of its turning so that the head 61 is held at a predetermined position (the position turned over 180.degree.) by a stopper 63.
Mechanisms of the above-described sort are however accompanied by the following drawbacks. Due to the existence of a clearance between the turning shaft 64 and the bearing 65, the magnetic head 61 is off-centered (i.e., deviated from the center) or tilted. When such off-centering or inclination takes place, the optimum positional relation between the head 61 and an associated magnetic tape is affected adversely so that the acoustic characteristics are lowered significantly. It has hence been necessary to provide a tape guide 67 on a side wall of the head 61 in order to maintain the precise positional relation between the head 61 and the tape.
Where the tape guide 67 is fixed on the side wall of the head 61, it is necessary to cause the head 61 to retreat once whenever it is desired to turn the head 61 over 180.degree. upon each change-over of the running direction of the tape. It is hence necessary, as shown in FIG. 7(a), to shift the head 61 back and forth, to say nothing of turning of the head 61. This has led to the need for a complex mechanism to shift the head 61. If the maximum turning radius of the head 61 is greater than one half of the height of a window 68 of a tape cassette, it is impossible to turn the head 61 within the cassette as depicted in FIG. 7(b). In this case, it is indispensable to cause the head 61 to retreat from the interior of the cassette. This requirement has resulted in problems such that the reverse operation of the tape running direction takes lots of time.